<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title><!DOCTYPE html>
        <html lang="en">
        <head>
        <meta charset="UTF-8">
        <title>Title</title>
    <style>
        .main{
            width: 500px;
            height: 500px;
            border: 1px solid #000;
            background-color: skyblue;
            display: flex;
            /*flex-flow: column nowrap;*/
        }

        .main .box{
            width: 100px;
            height: 100px;
            background-color: blueviolet;
            flex: 0 1 100%;
        }
    </style>
</head>
<body>
<div class="main">
    <div class="box">
        和其他神秘地区一样
    </div>
</div>
</body>
</html>
</title>
</head>
<body>

</body>
</html>
